Bryophytes, comprising mosses (??), liverworts (??) and hornworts
(???), are a group of small, green land plants characterized
by (a) the absence of vascular tissues and by (b) the unique
life history having a dominant gametophyte generation (?????),
which produces the sex organs (antheridia and archegonia) and
gametes (sperms and eggs). The sporophytes (???), which produce
spores, cannot live alone and is essentially dependant on the
gametophyte for water and nutrients.

Bryophytes are the second largest group of land plants, followed
angiosperms, with about 15,000 species worldwide. They can be
found in most terrestrial and some fresh water habitats except
marine environment. They are usually a few millimeters to several
centimeters in height, rendering them inconspicuous and easily
overlooked. They are normally associated with moist and shaded
environment, but a few species can tolerate a wide range of
harsh environments, e.g. alpine regions, deserts, and the Antarctic.